Wireless Networks

This book presents an overview of 802.11 networks, along with brief discussions of other wireless technologies. It also discusses ways to improve the mobility management and security aspect of IEEE 802.11 infrastructure networks. After the introduction, mobility management and security enhancement form the two major parts of the book. In the first part of the book, we look at the basic concepts and the performance analysis of the current IEEE 802.11 network standards was done. Under the current technology, when a mobile node moves from one access point to another, the handoff is not always smooth and connection may be dropped as a result. The reason for that is inherent in the mobility design problems of the existing implementations. For handoff to be smooth, the cumulative handoff delay should be around 50 msec or lesser for voice related applications. However, currently the handoff delay is of the order of several hundred milliseconds. This is contributed by delays such as - scan or probe delay, authentication delay and reassociation delay. Our contribution to mobility management is to propose a mobility prediction algorithm using location tracking and data mining, to propose a delay management approach that cuts down major delays, and to propose a two stage resource reservation scheme. In the second part of the book, IEEE 802.11 security analysis is done through war-driving, packet analysis, WEP (Wired Equivalent Privacy) cracking, ARP (Address Resolution Protocol) poisoning, and MAC (Medium Access Control) spoofing. Even if the wireless packets are encrypted, the header of each packet can reveal important information that can be used to perform spoofing attacks. To prevent some major spoofing attacks like ARP poisoning and MAC spoofing, we designed two secure versions of protocols, namely Secure Unicast Address Resolution Protocol (S-UARP) and Secure Dynamic Host Configuration protocol (S-DHCP).